Republicans were considering the implications of a night of mixed electoral fortunes on Wednesday, capped by the re-election of New Jersey governor Chris Christie who won decisively with a campaign that appealed to moderates but alienated the conservative wing of his party.

Christie's emphatic win in New Jersey cemented his position as a contender for the Republican presidential nomination in 2016 and provided a boost to moderates in the GOP who have been battling with hardline conservatives.

The victory in New Jersey contrasted with defeat in Virginia, were the Tea Party-backed Republican Ken Cuccinelli lost to Democrat Terry McAuliffe. The race was closer than expected, but nonetheless represented a blow to Republicans; the first time since 1973 the party in the White House has won the state's gubernatorial race.

The New Jersey and Virginia races differed in significant ways, and analysts cautioned against drawing hard-and-fast conclusions about the wider political landscape for Republicans.

But it was symbolic moment: a centre-right, pragmatic Republican triumphed in New Jersey, a solidly Democratic state, while a staunchly conservative Republican lost in Virginia, a traditional swing-state he had been tipped to win just a few months ago.

Polls indicated that anger over the government shutdown, which was sharply felt in parts of northern Virginia, as well as discomfort with Cuccinelli's deeply conservative views, handed the race to McAuliffe, a controversial Democratic fundraiser and close ally of Bill and Hillary Clinton.

In New York, a Democrat won the race for city mayor for the first time in 20 years, with a landslide victory for Bill de Blasio. In Alabama, a closely-watched Republican primary was won by Bradley Byrne, in what was considered a victory for the party establishment against another Tea Party-inspired candidate, Dean Young.

Christie, who is due to assume the powerful chairmanship of the Republican Governor's Association (RGA), was the most high-profile winner of the night. His election, which drew the support of African American, Latino and women voters who have elsewhere been deserting Republicans, catapults Christie to the ranks of front-runners in the 2016 Republican presidential nomination.

Other likely candidates include senators Rand Paul, Ted Cruz and Marco Rubio, who have all adopted staunchly conservative positions that appeal to their base but alienate the moderates and independent voters generally seen as essential to take the White House.

During his campaign, Christie made a virtue of working with Democrats such as president Obama on bipartisan issues – in contrast to Cruz and other the hardliners who were blamed for the recent federal government shutdown. He is also seen as much less divisive on social issues such as abortion and gun control.

He portrayed his victory as a triumph for his pragmatic, centrist brand of conservatism. "I know that if we can do this in Trenton, New Jersey, maybe the folks in Washington should tune into their TV sets, and see how it's done," he said during his acceptance speech. "I know tonight, a dispirited America, angry with their dysfunctional government in Washington will look to New Jersey and say: 'Is what I think happening really happening? Are people coming together?'"

Capitalising on a bad night for conservative factions in the GOP, the Republican campaign group Main Street Advocacy released an internet ad blaming conservative elements in the party for a succession of electoral defeats – directly criticising Tea Party-aligned advocacy groups such as Club for Growth and Freedom Works over the unpopular decision to force a government shutdown over Barack Obama's healthcare reforms.

Steve LaTaurette, the president of Main Street Advocacy, told the Guardian the elections in New Jersey, Virginia and Alabama represented a defeat for what he called the "far-right" in the GOP. A former Republican congressman, LaTaurette said the Virginia race was a particular blow.

"Even as conservative as Cuccinelli is, he could have prevailed but for the fact that his Tea Party allies in Congress leveraged this shutdown and drove people way, particularly in northern Virginia where a lot of people care about the government."

LaTaurette is at the vanguard of a group of business-orientated, more Republicans, who have decided take a more aggressive stance toward Tea Party factions.

"It is not a civil war, because our side has not [until now] fought back," he said. "I would argue that it is more a battle for the Republican party, moving forward to the 2016 presidential election. It doesn't have to be bloody, it doesn't have to be nasty, but it does have to be fought."

Hardline elements in the party fought back. Amy Kremer, chairwoman of the Tea Party Express, blamed Cuccinelli's defeat on the GOP, pointing out the Republican National Committee spent just $3m to the Virginia election –compared to the $9m spent in the gubernatorial race in 2009, which the party won.

Kremer insisted the Tea Party wing of the party was undamaged. "We are going to be an important factor in 2014," she told CNN, a nod to next year's midterm elections when seats will be up for grabs in both the House and Senate. "We are not going away."

Cuccinelli also blamed the $15m gulf in campaign finance between the two candidates for his defeat and insisted the last-minute recovery in his support showed the unpopularity of Democrat healthcare reforms, which dominated the final days of the campaign.

In the weeks leading up to the vote, some polls showed McAulliffe with a double-digit lead over Cuccinelli, but in the end won by just 3 percentage points.

"Despite being outspent by an unprecedented $15m, this race came down to the wire because of Obamacare," Cuccinelli told supporters in the Richmond.

Amid heated debate over the ramifications of the elections, one notable similarity between the major victors, Christie and McAuliffe, was that they both significantly outspent their rivals, deploying negative attack ads to undermine their opponents.

"We shouldn't lose focus on the fundamentals," said Republican strategist Martin Baker, a former adviser to Newt Gingrich's presidential campaign. He added that the races are "textbook examples that money and mechanics remain critical to a successful campaign."